1. Field of the Disclosure
The present subject matter relates to systems and methods for automated expression of fluid from a container. More particularly, the present subject matter relates to systems and methods for automated expression of a fluid from and/or into a blood component-containing container.
2. Description of Related Art
Whole blood is typically collected from donors in what is commonly called a manual collection procedure. In such a procedure, whole blood is collected directly from the donor into a primary collection container. The whole blood may be separated into its constituents by various means, including centrifugation. Once the blood has been separated into its component parts, the component may be variously disposed of, depending on the nature of the particular processing procedure. For example, one or more of the separated components (e.g., red cells) may be stored for later administration to a patient and other components (e.g., plasma or platelets) may be collected and pooled with like components from other donors for administration or processing at a later time. In other procedures, one of the separated components may be processed and returned to the blood source, as is the case in automated therapeutic plasma exchanges or platelet-only collections.
In manual collection, blood is typically drawn from a blood source (such as a healthy donor) into a pre-assembled and pre-sterilized fluid circuit having a number of flexible containers connected together by tubing. The whole blood is typically directed into a primary collection container, where it is mixed with an amount of anticoagulant. After initial collection, the primary container, with any attached satellite containers, is transported to a processing facility which may be at the same site as the collection, or elsewhere, for further processing. There, the anticoagulated blood is separated into its components (e.g., by centrifugation) and one or more of the components is flowed or expressed out of the primary container. In certain blood processing systems employed in such processing, an integrated apparatus is provided for both separating the blood into its constituents and then expressing one or more of the constituents from the container. One possible disadvantage with existing blood processing systems is that they typically rely on moving mechanical parts (e.g., peristaltic pumps), which are subject to simple mechanical failure due to age or any of a number of other reasons. If even one of the many parts of the system malfunctions, the entire system may become unusable, thereby defeating one of the purposes of an “all-in-one” or integrated processing system.
An alternative to “all-in-one” type blood processing systems is the use of separate separation and expression devices, such as a centrifuge (for blood separation) and an expresser (for expression of a blood component from a container having a plurality of blood components). An exemplary system for separately fractionating blood and expressing blood components is described in U.S. Pat. No. 6,994,790 to Corbin, Ill. et al., which is incorporated herein by reference. Typically, the expresser includes a pair of parallel or hingedly connected plates. If the plates are parallel, the container is placed therebetween and the plates are moved toward each other to exert pressure on the container and express one or more of the blood components out of a port or opening of the container. If the plates are hingedly connected, the container is placed in the space between the plates and then the plates are pivoted toward each other to exert pressure on the container and thereby express one or more of the blood components out of a port or opening of the container. Other known expression devices include, but are not limited to, those of the type described in U.S. Pat. Nos. 5,547,108 and 5,695,653 to Gsell et al., both of which are incorporated herein by reference.
Another disadvantage of known processing systems and expressers is that it will sometimes be desirable to do more than merely express a blood component from a container holding a plurality of blood components. For example, it may be advantageous to express a component into a satellite container, add a storage solution or additive to a blood component remaining in the original container, mix the component and additive, and then express any excess air from the containers. Known expressers and systems are not suited for automating all of these procedures and typically require substantial operator intervention and oversight to carry out all of the desired processing steps. Manual intervention potentially includes the risk of human error. It would be advantageous to avoid or limit such a risk by providing a single device capable of automating all of the necessary post-collection and/or post-separation processing steps.